D-lactate production in the acorn barnacle Balanus glandula (Darwin, 1854) (Cirripedia: Balanidae) under emersion stress

2020 ◽  
Vol 40 (6) ◽  
pp. 739-745
Author(s):  
Xenia L Rangaswami ◽  
Gordon T Ober ◽  
Sarah E Gilman
Keyword(s):  
Anaerobic Metabolism ◽  
Lactate Production ◽  
Aerobic Respiration ◽  
Balanus Glandula ◽  
Air Exposure ◽  
Air Temperatures ◽  
Acorn Barnacle ◽  
The Pacific ◽  
Response To Stress ◽  
Us West

Abstract Anaerobic metabolism is an important response to stress in many organisms. Intertidal species often face heat stress during low tide. Balanus glandula (Darwin, 1854) is a high-shore intertidal barnacle common to the Pacific that experiences prolonged low-tide air exposure. It is not known whether B. glandula uses anaerobic metabolism during emersion, or if its use varies by latitude. We measured low tide D-lactate production in two US west coast populations of B. glandula separated by 14 degrees of latitude. We exposed barnacles to seven low-tide air temperatures (10, 15, 20, 25, 30, 35, and 38 °C) for which aerobic respiration has been previously measured. Our northern population of B. glandula increased D-lactate production at high air temperatures where aerobic metabolic depression is known to occur, indicating sublethal stress. In contrast, our southern population showed little increase in D-lactate over the same temperature range, coincident with high aerobic respiration across those temperatures. In a second experiment, we quantified D-lactate at 1, 2, and 6 hours post-emersion for northern B. glandula exposed to either a 10 or 38 °C low tide, to measure their potential lactate usage. While D-lactate was elevated at 38 °C compared to the 10 °C control immediately following low tide exposure, it dropped to control levels, and was likely excreted, within 1 hour of re-immersion. Our results suggest that the low latitude population of B. glandula may be more resilient to climate change than its high latitude counterpart in the absence of adaptation, which has strong implications for species distribution.

scholarly journals Effects of intertidal position on metabolism and behavior in the acorn barnacle, Balanus glandula

2021 ◽  
Author(s):  
Kali M Horn ◽  
Michelle E Fournet ◽  
Kaitlin A Liautaud ◽  
Lynsey N Morton ◽  
Allie M Cyr ◽  
...  
Keyword(s):  
Body Size ◽  
Food Availability ◽  
Intertidal Zone ◽  
Anaerobic Metabolism ◽  
Beat Frequency ◽  
Balanus Glandula ◽  
Metabolic Capacity ◽  
Air Exposure ◽  
Ldh Activity ◽  
Consumption Rates

Abstract The intertidal zone is characterized by persistent, tidally-driven fluctuations in both abiotic (e.g., temperature, [O2], salinity) and biotic (e.g., food availability, predation) factors, which make this a physiologically challenging habitat for resident organisms. The relative magnitude and degree of variability of environmental stress differs between intertidal zones, with the most extreme physiological stress often being experienced by organisms in the high intertidal. Given that so many of the constantly shifting parameters in this habitat are primary drivers of metabolic rate (e.g., temperature, [O2], food availability), we hypothesized that sessile conspecifics residing in different tidal zones would exhibit distinct ‘metabolic phenotypes,’ a term we use to collectively describe the organisms’ baseline metabolic performance and capacity. To investigate this hypothesis, we collected acorn barnacles (Balanus glandula) from low, mid, and high intertidal positions in San Luis Obispo Bay, CA and measured a suite of biochemical (whole-animal citrate synthase (CS) and lactate dehydrogenase (LDH) activity, aerial [D-lactate]), physiological (O2 consumption rates), morphological (body size) and behavioral (e.g., cirri beat frequency, % time operculum open) indices of metabolism. We found tidal zone-dependent differences in B. glandula metabolism that primarily related to anaerobic capacity, cirral activity patterns and body size. Barnacles from the low intertidal tended to have a greater capacity for anaerobic metabolism (i.e., increased LDH activity, increased baseline [D-lactate]), have reduced cirral beating activity—and presumably reduced feeding—when submerged, and be smaller in size compared to conspecifics in the high intertidal. We did not, however, see any D-lactate accumulation in barnacles from any tidal height throughout the 96 h of air exposure. This trend indicates that the enhanced capacity of low intertidal barnacles for anaerobic metabolism may have evolved to support metabolism during more prolonged episodes of emersion or during events other than emersion (e.g., coastal hypoxia, predation). There were also no significant differences in CS activity or baseline oxygen consumption rates (in air or seawater at 14˚C) across tidal heights, which implies that aerobic metabolic capacity may not be as sensitive to tidal position as anaerobic processes. Understanding how individuals occupying different shore heights differ in their metabolic capacity becomes increasingly interesting in the context of global climate change, given that the intertidal zone is predicted to experience even greater extremes in abiotic stress.

The invasion of the acorn barnacle Balanus glandula in the south-western Atlantic 40 years later

2007 ◽  
Vol 87 (5) ◽  
pp. 1219-1225 ◽  
Author(s):  
Evangelina Schwindt
Keyword(s):  
High Rate ◽  
Rocky Shores ◽  
Balanus Glandula ◽  
The South ◽  
Western Atlantic ◽  
Geographical Patterns ◽  
Rate Of Spread ◽  
Acorn Barnacle ◽  
The Pacific ◽  
Successful Invader

The acorn barnacle Balanus glandula (Darwin 1854) is native to the Pacific coast of North America and was accidentally introduced in Argentina in the early 1970s. Here the invasion status of this species is reviewed in the south-western Atlantic focusing on geographical patterns of density, cover, biomass, size and recruitment, and also estimating its rate of spread. Field surveys along rocky shores and a literature review show that B. glandula invaded most of the rocky shores of Argentina at a high rate of spread. Density and cover of barnacles do not follow a latitudinal trend; instead both variables show a bimodal pattern with the highest values in two distant locations (Puerto Lobos and Bahía Bustamante). However, the size of the barnacles increases with latitude, and is positively related to biomass. Recruitment of this species varies between wave exposed and protected areas, and over time. At lower latitudes barnacles recruit in winter, while at higher latitudes they recruit in spring and summer. The differences observed in density and recruitment suggest that along the Argentinean coast, oceanographic processes have a stronger influence in the distribution and success of the barnacles than the gradient in wave exposure. Balanus glandula is a successful invader which has completely re-shaped the native intertidal landscape. Moreover, considering the wide temperature range that this barnacle tolerates in native and invaded regions, the entire coastline of South America could be colonized by this species in the future.

scholarly journals Retrieval of Summer Sea Ice Concentration in the Pacific Arctic Ocean from AMSR2 Observations and Numerical Weather Data Using Random Forest Regression

2021 ◽  
Vol 13 (12) ◽  
pp. 2283
Author(s):  
Hyangsun Han ◽  
Sungjae Lee ◽  
Hyun-Cheol Kim ◽  
Miae Kim
Keyword(s):  
Random Forest ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Open Water ◽  
The Arctic ◽  
Atmospheric Effects ◽  
Sea Ice Concentration ◽  
Air Temperatures ◽  
The Pacific ◽  
Ice Concentration

The Arctic sea ice concentration (SIC) in summer is a key indicator of global climate change and important information for the development of a more economically valuable Northern Sea Route. Passive microwave (PM) sensors have provided information on the SIC since the 1970s by observing the brightness temperature (TB) of sea ice and open water. However, the SIC in the Arctic estimated by operational algorithms for PM observations is very inaccurate in summer because the TB values of sea ice and open water become similar due to atmospheric effects. In this study, we developed a summer SIC retrieval model for the Pacific Arctic Ocean using Advanced Microwave Scanning Radiometer 2 (AMSR2) observations and European Reanalysis Agency-5 (ERA-5) reanalysis fields based on Random Forest (RF) regression. SIC values computed from the ice/water maps generated from the Korean Multi-purpose Satellite-5 synthetic aperture radar images from July to September in 2015–2017 were used as a reference dataset. A total of 24 features including the TB values of AMSR2 channels, the ratios of TB values (the polarization ratio and the spectral gradient ratio (GR)), total columnar water vapor (TCWV), wind speed, air temperature at 2 m and 925 hPa, and the 30-day average of the air temperatures from the ERA-5 were used as the input variables for the RF model. The RF model showed greatly superior performance in retrieving summer SIC values in the Pacific Arctic Ocean to the Bootstrap (BT) and Arctic Radiation and Turbulence Interaction STudy (ARTIST) Sea Ice (ASI) algorithms under various atmospheric conditions. The root mean square error (RMSE) of the RF SIC values was 7.89% compared to the reference SIC values. The BT and ASI SIC values had three times greater values of RMSE (20.19% and 21.39%, respectively) than the RF SIC values. The air temperatures at 2 m and 925 hPa and their 30-day averages, which indicate the ice surface melting conditions, as well as the GR using the vertically polarized channels at 23 GHz and 18 GHz (GR(23V18V)), TCWV, and GR(36V18V), which accounts for atmospheric water content, were identified as the variables that contributed greatly to the RF model. These important variables allowed the RF model to retrieve unbiased and accurate SIC values by taking into account the changes in TB values of sea ice and open water caused by atmospheric effects.

A preliminary analysis of ingestion and egestion of microplastic fibres in the acorn barnacle Balanus glandula

2021 ◽  
Vol 542-543 ◽  
pp. 151589
Author(s):  
Hailey L. Davies ◽  
Haley Robb ◽  
Kieran D. Cox ◽  
Garth A. Covernton ◽  
Tao M. Eastham ◽  
...  
Keyword(s):  
Preliminary Analysis ◽  
Balanus Glandula ◽  
Acorn Barnacle

Effects of varying hematocrit on intestinal oxygen uptake in neonatal lambs

1985 ◽  
Vol 248 (4) ◽  
pp. G432-G436 ◽  
Author(s):  
I. R. Holzman ◽  
B. Tabata ◽  
D. I. Edelstone
Keyword(s):  
Blood Flow ◽  
Anaerobic Metabolism ◽  
Lactate Production ◽  
Oxygen Availability ◽  
Intestinal Blood Flow ◽  
Oxygen Extraction ◽  
Base Line ◽  
Wide Range ◽  
O2 Extraction ◽  
Neonatal Lambs

We chronically catheterized 15 newborn lambs (9.5 +/- 2.8 days) and measured intestinal blood flow (Qi) by the radionuclide microsphere technique at hematocrit levels ranging from 10 to 55%. Seven animals were made progressively anemic and eight polycythemic by means of exchange transfusions. Using the Fick principle, we calculated intestinal oxygen delivery (Di o2), oxygen consumption (Vi o2), and oxygen extraction. Initial base-line values were Qi = 195.5 ml . min-1 . 100 g intestine-1, Di o2 = 22.1 ml . min-1 . 100 g-1, Vi o2 = 4.8 ml . min-1 . 100 g-1, and O2 extraction = 22.5%. As the hematocrit was lowered, Di o2 decreased and O2 extraction increased and vice versa when the hematocrit was raised. Vi o2 remained constant, but Qi did not correlate with changes in hematocrit. However, intestinal blood flow, as a percent distribution of total blood flow, decreased with lower hematocrit levels. At no time was there any evidence of anaerobic metabolism as measured by excess lactate production. Our data indicate that the intestines of neonatal lambs are capable of maintaining their metabolic needs over a wide range of oxygen availability induced by a changing hematocrit. The primary mechanism is through alteration of oxygen extraction. Within the range of our experiments, no critically low oxygen availability was attained at which anaerobic metabolism became significant.

scholarly journals Redirecting Reductant Flux into Hydrogen Production via Metabolic Engineering of Fermentative Carbon Metabolism in a Cyanobacterium

2010 ◽  
Vol 76 (15) ◽  
pp. 5032-5038 ◽  
Author(s):  
Kelsey McNeely ◽  
Yu Xu ◽  
Nick Bennette ◽  
Donald A. Bryant ◽  
G. Charles Dismukes
Keyword(s):  
Metabolic Engineering ◽  
Carbon Metabolism ◽  
Anaerobic Metabolism ◽  
Lactate Production ◽  
Energy Conversion Efficiency ◽  
Liquid Chromatography Mass Spectrometry ◽  
Wild Type ◽  
Photoautotrophic Growth ◽  
Principal Source ◽  
Anaerobic Conversion

ABSTRACT Some aquatic microbial oxygenic photoautotrophs (AMOPs) make hydrogen (H2), a carbon-neutral, renewable product derived from water, in low yields during autofermentation (anaerobic metabolism) of intracellular carbohydrates previously stored during aerobic photosynthesis. We have constructed a mutant (the ldhA mutant) of the cyanobacterium Synechococcus sp. strain PCC 7002 lacking the enzyme for the NADH-dependent reduction of pyruvate to d-lactate, the major fermentative reductant sink in this AMOP. Both nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS) metabolomic methods have shown that autofermentation by the ldhA mutant resulted in no d-lactate production and higher concentrations of excreted acetate, alanine, succinate, and hydrogen (up to 5-fold) compared to that by the wild type. The measured intracellular NAD(P)(H) concentrations demonstrated that the NAD(P)H/NAD(P)+ ratio increased appreciably during autofermentation in the ldhA strain; we propose this to be the principal source of the observed increase in H2 production via an NADH-dependent, bidirectional [NiFe] hydrogenase. Despite the elevated NAD(P)H/NAD(P)+ ratio, no decrease was found in the rate of anaerobic conversion of stored carbohydrates. The measured energy conversion efficiency (ECE) from biomass (as glucose equivalents) converted to hydrogen in the ldhA mutant is 12%. Together with the unimpaired photoautotrophic growth of the ldhA mutant, these attributes reveal that metabolic engineering is an effective strategy to enhance H2 production in AMOPs without compromising viability.

Glucose uptake by diaphragms from rats subjected to hemorrhagic shock

1964 ◽  
Vol 206 (2) ◽  
pp. 317-320 ◽  
Author(s):  
William R. Drucker ◽  
John C. DeKiewiet
Keyword(s):  
Skeletal Muscle ◽  
Hemorrhagic Shock ◽  
Glucose Uptake ◽  
Anaerobic Metabolism ◽  
Lactate Production ◽  
Bicarbonate Buffer ◽  
Metabolic Alterations ◽  
Shock Models ◽  
The Media ◽  
Intracellular Energy

The marked metabolic alterations that occur in hemorrhagic shock have been ascribed to tissue anoxia occasioned by hypovolemia. Other investigators, utilizing different shock models, have explained the initial metabolic changes as secondary to humoral changes. In skeletal muscle, anoxia is known to cause an increased glucose uptake, whereas epinephrine causes a decreased uptake. The present work was undertaken to explore some alterations in carbohydrate metabolism during hemorrhagic shock in rats, when both tissue anoxia and an altered humoral state are present. Hemidiaphragms from rats subjected to a standardized hemorrhagic shock procedure and from control rats were excised and incubated aerobically in bicarbonate buffer containing glucose. After 1 hr of incubation aliquots of the media were analyzed for glucose and lactate. The results demonstrated a significantly greater glucose uptake and lactate production by the diaphragms from the bled rats. The data suggest that, during hemorrhagic shock in rats, tissue anoxia leads to a predominance of anaerobic metabolism and a severe depletion of intracellular energy, resulting in an increased uptake of glucose in skeletal muscle despite the concomitant altered humoral state which ordinarily would inhibit glucose uptake.

scholarly journals Climate Extreme Seeds a New Domoic Acid Hotspot on the US West Coast

2020 ◽  
Vol 2 ◽  
Author(s):  
Vera L. Trainer ◽  
Raphael M. Kudela ◽  
Matthew V. Hunter ◽  
Nicolaus G. Adams ◽  
Ryan M. McCabe
Keyword(s):  
Early Warning ◽  
West Coast ◽  
Domoic Acid ◽  
Large Scale ◽  
Early Warning Systems ◽  
Warning Systems ◽  
Dungeness Crab ◽  
The Pacific ◽  
The Us ◽  
Us West

A heatwave that blanketed the northeast Pacific Ocean in 2013–2015 had severe impacts on the marine ecosystem through altered species composition and survival. A direct result of this marine heatwave was a sustained, record-setting harmful algal bloom (HAB), caused by the toxigenic diatom, Pseudo-nitzschia, that led to an unprecedented delay in harvest opportunity for commercial Dungeness crab (Metacarcinus magister) and closure of other recreational, commercial and tribal shellfish harvest, including razor clams. Samples collected during a cruise in summer 2015, showed the appearance of a highly toxic “hotspot” between Cape Mendocino, CA and Cape Blanco, OR that was observed again during cruises in the summers of 2016–2018. The transport of toxic cells from this retentive site northward during wind relaxations or reversals associated with storms resulted in economically debilitating delay or closure of Dungeness crab harvest in both northern California and Oregon in 2015–2019. Analyses of historic large-scale Pseudo-nitzschia HABs have shown that these events occur during warm periods such as El Niño, positive phases of the Pacific Decadal Oscillation, or the record-setting marine heatwave. In order to reduce the impacts of large-scale HABs along the west coast of North America, early warning systems have been developed to forewarn coastal managers. These early warning systems include the Pacific Northwest and California HAB Bulletins, both of which have documented elevated domoic acid and increased risk associated with the northern California hotspot. These early warnings enable mitigative actions such as selective opening of safe harvest zones, increased harvest limits during low risk periods, and early harvest in anticipation of impending HAB events. The aims of this study are to show trends in nearshore domoic acid along the US west coast in recent years, including the recent establishment of a new seed bed of highly-toxic Pseudo-nitzschia, and to explore how early warning systems are a useful tool to mitigate the human and environmental health and economic impacts associated with harmful algal blooms.

scholarly journals Ecological Load and Balancing Selection in Circumboreal Barnacles

2020 ◽  
Author(s):  
Joaquin C B Nunez ◽  
Stephen Rong ◽  
Alejandro Damian-Serrano ◽  
John T Burley ◽  
Rebecca G Elyanow ◽  
...  
Keyword(s):  
Environmental Variability ◽  
Balancing Selection ◽  
Spatial Scales ◽  
Functional Variation ◽  
Ion Regulation ◽  
Juvenile Dispersal ◽  
Acorn Barnacle ◽  
The Pacific ◽  
Complex Population ◽  
The Face

Abstract Acorn barnacle adults experience environmental heterogeneity at various spatial scales of their circumboreal habitat, raising the question of how adaptation to high environmental variability is maintained in the face of strong juvenile dispersal and mortality. Here, we show that 4% of genes in the barnacle genome experience balancing selection across the entire range of the species. Many of these genes harbor mutations maintained across 2 My of evolution between the Pacific and Atlantic oceans. These genes are involved in ion regulation, pain reception, and heat tolerance, functions which are essential in highly variable ecosystems. The data also reveal complex population structure within and between basins, driven by the trans-Arctic interchange and the last glaciation. Divergence between Atlantic and Pacific populations is high, foreshadowing the onset of allopatric speciation, and suggesting that balancing selection is strong enough to maintain functional variation for millions of years in the face of complex demography.

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